Hey man I had the same problem. What I did was sit in my car after I turned the car off. After about 2 min the ac fan turned on then turned off, and it kept doing it over and over. This killed my battery. Whats was wrong with my car was the "Final Stage Resistor". I replaced that, and put a new battery(covered under battery warranty) and everything worked perfect. It was a very easy job and the part is about $60.